Answer:
Standard deviation = 3
Explanation:
Given


Required
Determine the standard deviation
First, we need to determine the variance;

This gives:



Know that:

Where SD represents standard deviation
This gives

Take square root


Answer:
Explanation:
Height covered = 12m
time to fall by 12 m
s = 1/2 gt²
12 = 1/2 g t²
t = 1.565 s
Horizontal distance of throw
= 8.5 x 1.565
= 13.3 m
This distance is to be covered by dog during the time ball falls ie 1.565 s
Speed of dog required = 13.3 / 1.565
= 8.5 m /s
b ) dog will catch the ball at a distance of 13.3 m .
Answer:anion followed by cation
Explanation: